Question: $-\dfrac{1}{6} + \dfrac{7}{10} = {?}$
Solution: $ = - {\dfrac{1 \times 5}{6 \times 5}} + {\dfrac{7 \times 3}{10 \times 3}} $ $ = - {\dfrac{5}{30}} + {\dfrac{21}{30}} $ $ = - \dfrac{{5} + {21}}{30} $ $ = \dfrac{16}{30}$